Biomedical Engineering Reference
In-Depth Information
5.12 Virial stress versus displacement plots for (a) microstructures M1
and M2 and (b) microstructures M3, M4, M5, and M6.
5.13 Crack propagation as a function of displacement for
microstructure (a) M1 and (b) M2.
stress-displacement profile with or without initial cracks. Microstructure
M2 has an interface, as shown in Fig. 5.8, which leads to lower peak stress
values. However, overall, the area under the stress-strain curve in the case of
M2 is higher. This indicates that the presence of an interface leads to an
increase in toughness for Si
3
N
4
. The presence of an initial crack does not
have any significant effect on the stress-strain profile for both M1 and M2.
This may be attributed to the long-range Coulumbic interactions that are
not affected by the switching off of interatomic interactions in the crack
plane.
As noted earlier, virial stress is an internal quantity signifying the
resistance of atomistic system to external load or pressure. In this case,
